Path traversal in Linux kernel - CVE-2026-68083
Published: August 13, 2026
Vulnerability identifier: #VU142241
CSH Severity: Medium
CVSS v4: 7.6 [CVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:N/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N]
CVE-ID: CVE-2026-68083
CWE-ID: CWE-22
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vulnerability details
The vulnerability allows a remote user to access files outside the exported share.
The vulnerability exists due to improper limitation of a pathname to a restricted directory in ksmbd_vfs_kern_path_create() when handling SMB create, mkdir, or hardlink operations with crafted path components. A remote user can race a missing path component and use a ".." path element to access files outside the exported share.
Exploitation requires authentication to the SMB service and a race condition between the rooted lookup and the create path resolution.
Affected software
Linux kernel
Ubuntu
linux (Ubuntu package)
linux-gcp (Ubuntu package)
Ubuntu
linux (Ubuntu package)
linux-gcp (Ubuntu package)
How to mitigate CVE-2026-68083
Install security update from vendor's repository.
Linux kernel - update to 7.0 rc3
linux (Ubuntu package) - addressed in versions 7.0.0-34.34, 7.0.0-34.34.1, 7.0.0-34.34~24.04.1, 7.0.0-1012.12~24.04.1, 7.0.0-1013.13, 7.0.0-1013.13~24.04.1, 7.0.0-1014.14, 7.0.0-1020.20
linux-gcp (Ubuntu package) - addressed in versions 7.0.0-1013.13, 7.0.0-1013.13~24.04.1, 7.0.0-1014.14
linux (Ubuntu package) - addressed in versions 7.0.0-34.34, 7.0.0-34.34.1, 7.0.0-34.34~24.04.1, 7.0.0-1012.12~24.04.1, 7.0.0-1013.13, 7.0.0-1013.13~24.04.1, 7.0.0-1014.14, 7.0.0-1020.20
linux-gcp (Ubuntu package) - addressed in versions 7.0.0-1013.13, 7.0.0-1013.13~24.04.1, 7.0.0-1014.14